Taken from – Marks and Markings of Weights and Measures of The British Isles by Carl Ricketts with John Douglas.

The following is but the simplest of detail taken from this very fine book. Carl Ricketts has provided me with a ten page article which covers the subject in far more detail than the relatively straightforward tables copied and shown here. I will be pleased to email a copy of the article to any who would wish to further test their interest before attempting to obtain a copy of the book from either the author directly or from The Pewter Society.

The Collector’s Interest

Measuring capacity is not difficult although interpreting the results can be a problem. We should measure all old vessels for the eye alone cannot easily distinguish what measurement may reveal. Differences in proportions can mask both over- and under-capacity, and result in historically interesting items passing unnoticed. N.B. having an ‘unusual’ capacity does not automatically place the object earlier than c1826 as many local and customary measures continued to be used regionally during most of the 19th Century. They give interest through their mute testimony to the strength of regional and local preferences and the tenacity of both the trade and the public in continuing to use them. Thankfully from our viewpoint they frustrated Parliament’s intentions, which legislated for their removal in the 1835 Act 5 & 6 Will IV c63.

* John Renold’s 1641 Pottle is an extant standard (wine) measure based on a gallon of c250 cubic inches which probably represented the continuing use of Henry VII’s wine standard. The Guernsey gallon was of equivalent capacity.

CONVERSION FACTOR: 1 FLUID OUNCE = 28.413 MILLILITRES

EXAMPLES OF MARKS INDICATING PRE-IMPERIAL CAPACITY

Old English Ale Standard

Scots Standards

Old English Wine Standard

A rare mark on a mug c1790 by William Bancks of Bewdley to show it was of Old English Ale standard capacity

45I S

Scots Ale

3I G4

Scots Stirling

WINE

56I S

Other examples of relationship marks engraved on pewter vessels:

1/40 IG

Scots Ale Gill (4.0 fl.oz)

"1/42nd of an Imperial Gallon"

Scots Stirling Gill (3.8 fl.oz)

"One Sixth less than an Imperial Pint"

Wine Pint (16.7 fl.oz)

"Warranted Winchester Measure"

On pearlware mug (19.5 fl oz Winchester Measure) dating from last quarter of the 18th Century